4CZB

Structure of the sodium proton antiporter MjNhaP1 from Methanocaldococcus jannaschii at pH 8.

Summary for 4CZB

• Entry DOI: 10.2210/pdb4czb/pdb
• Related: 4CZ8 4CZ9 4CZA
• Descriptor: NA(+)/H(+) ANTIPORTER 1, POTASSIUM ION, TRIS(HYDROXYETHYL)AMINOMETHANE, ... (4 entities in total)
• Functional Keywords: membrane protein, antiporter, transporter, exchanger, cpa
• Biological source: METHANOCALDOCOCCUS JANNASCHII; More
• Cellular location: Cell membrane ; Multi-pass membrane protein : Q60362 Q60362
• Total number of polymer chains: 4
• Total formula weight: 184251.00

Authors

Woehlert, D.,Paulino, C.,Kapotova, E.,Kuhlbrandt, W.,Yildiz, O. (deposition date: 2014-04-16, release date: 2014-12-10, Last modification date: 2023-12-20)

Primary citation

Paulino, C.,Woehlert, D.,Yildiz, O.,Kuhlbrandt, W.
3D Em Map of the Sodium Proton Antiporter Mjnhap1 from Methanocaldococcus Jannaschii
Elife, 3:-, 2014

PubMed Abstract: Sodium/proton antiporters are essential for sodium and pH homeostasis and play a major role in human health and disease. We determined the structures of the archaeal sodium/proton antiporter MjNhaP1 in two complementary states. The inward-open state was obtained by x-ray crystallography in the presence of sodium at pH 8, where the transporter is highly active. The outward-open state was obtained by electron crystallography without sodium at pH 4, where MjNhaP1 is inactive. Comparison of both structures reveals a 7° tilt of the 6 helix bundle. (22)Na(+) uptake measurements indicate non-cooperative transport with an activity maximum at pH 7.5. We conclude that binding of a Na(+) ion from the outside induces helix movements that close the extracellular cavity, open the cytoplasmic funnel, and result in a ∼5 Å vertical relocation of the ion binding site to release the substrate ion into the cytoplasm.

PubMed: 25426803
DOI: 10.7554/ELIFE.03583

Experimental method

X-RAY DIFFRACTION (3.5 Å)